I just wanted to pass along something that I recently learned from the folks at B/K, and also from Bill here:

If you have one of the early EPH Flex Mode radios, you may not be able to program it for narrow band operation from the keypad. The easiest way to tell is to go into the programming mode. If you enter the passcode and the radio displays "PASS", then you CAN select narrow or wide band from the keypad. If the radio does NOT display "PASS", then you can NOT.

However, not all is lost..... ANY Flex-Mode radio can be programmed for narrow band operation, via the programming software. If you think your users will need to program a narrow channel, you can program, via the software, one channel to be narrow band. The user can then go into the keypad programming, set the frequencies and/or tones for that channel, and the channel will stay narrow band. This assumes you have room in your programming to have an "extra" channel to make narrow band.